The present invention relates to a method and apparatus for producing a tire blank or green tire on a curving apparatus that includes a fixing head system having two rotatabIe and axially movable, one-piece bead-holding disks.
During the production of a green tire within the framework of a two-stage manufacture, a tire carcass is first wrapped upon a winding drum and is provided with the bead cores and core profile. The cylindrical carcass member that is produced in this manner is subsequently provided with a toroidal shape on a curving apparatus and is thereby connected with the belt unit.
With heretofore known methods for producing green tires, the prefabricated carcass member is temporarily stored and is subsequently manually placed upon the curving apparatus. Essentially two types of curving apparatus are known. With a first type, grooved or hooked fixing heads are provided that are equipped with segmented bead-holding disks. The segments can be drawn together to such an extent that it is just possible to place the carcass on the apparatus. Unfortunately, such an apparatus has the drawback that it is very expensive to manufacture and operate the segments. Furthermore, gaps between the segments result in marks on the green tire.
With the other known type of curving apparatus, fixing heads having one-piece, rigid, axially movable disks are provided. This apparatus has the drawback that the carcass must be manually and forcibly placed upon the apparatus, and in particular at an angle to the bead-holding disks. Furthermore, the holding disks must be moved very close together in order to make it possible to mount the carcass member. This necessitates long paths of travel for the disks and hence a greater expenditure of time for the curving process.
It is therefore an object of the present invention to provide a method that permits an automatic placement of the carcass, and also provides an apparatus where the means for accommodating the carcass have a simple construction and are as sturdy as possible.